21.4 Insulated means separated from other conducting surfaces by a
dielectric substance, (including air-space) offering a high resistance to the
passage of current.Air space when used
as insulation shall be maintained by permanently forming the conductor or by
adding additional mechanical means (e.g. spreader bar).When an object is said to be insulated, it is
understood to be insulated in a suitable manner for the condition to which it
is normally subjected.

Strikeout
and Underline Version

Rule 21.4

21.4 Insulated means separated from other conducting surfaces by a
dielectric substance, (including air-space) offering a high resistance to the
passage of current.Air space when used
as insulation shall be maintained by permanently forming the conductor or by
adding additional mechanical means (e.g. spreader bar).When an object is said to be insulated, it is
understood to be insulated in a suitable manner for the condition to which it
is normally subjected.

21.2 Grounded means connected to earth by a ground connection
or by an unintentional conducting path.

(1) If an impedance of less than 25 ohms
is not obtained, the equivalent of a ground conductor not less than No. 6
AWG copper connected to two corrosion resisting rods, not less than 1/2 inch
in diameter and 8 feet in length and continuous throughout, driven to a minimum
depth of 8 feet in the earth at not less than 6 foot centers, will be considered
an effective ground for the purpose of these rules.

(2) Where a common neutral system is installed,
the grounding provisions for such systems, as covered in
Rule 59.4
, shall apply.

B. Permanently Grounded refers to time, and means
grounded while the equipment concerned is in place under the conditions specified
in the rules.

C. Securely Grounded means connected to earth through a
metal surface in good contact with the earth (soil, rock, etc.) such as the
contact of anchor rods or metal poles set directly in the ground. Metal poles
set in concrete are considered as grounded but will not be considered as securely
grounded.

Final Version

Rule 21.4

21.4 Grounded means connected to earth by a ground connection
or by an unintentional conducting path.

(1) If an impedance of less than 25 ohms
is not obtained, the equivalent of a ground conductor not less than No. 6
AWG copper connected to two corrosion resisting rods, not less than 1/2 inch
in diameter and 8 feet in length and continuous throughout, driven to a minimum
depth of 8 feet in the earth at not less than 6 foot centers, will be considered
an effective ground for the purpose of these rules.

(2) Where a common neutral system is installed,
the grounding provisions for such systems, as covered in Rule 59.4
, shall apply.

B. Permanently Grounded refers to time, and means
grounded while the equipment concerned is in place under the conditions specified
in the rules.

C. Securely Grounded means connected to earth through a
metal surface in good contact with the earth (soil, rock, etc.) such as the
contact of anchor rods or metal poles set directly in the ground. Metal poles
set in concrete are considered as grounded but will not be considered as securely
grounded.